In situ molded thermal barriers

ABSTRACT

The invention provides methods, systems, and devices for installing thermal barriers in openings or gaps in or between structures such as walls, ceilings, and floors. At least one thermal barrier molding bag is positioned in the hole or gap, and a flowable firestop material that is operative to cure or harden, such as a hydratable cementitious slurry, is introduced into the bag to mold a barrier in the hole or gap.

FIELD OF THE INVENTION

[0001] The present invention relates to building structures, and moreparticularly to moldable thermal barriers for “head-of-wall” jointassemblies between top of walls and ceilings, “perimeter” joints betweenfloors and vertical walls, and other joints, gaps, or holes in buildingstructures.

BACKGROUND OF THE INVENTION

[0002] Firestops are thermal barrier materials or combinations ofmaterials used for filling gaps and openings such as in the jointsbetween fire-rated walls and/or floors of buildings. For example,firestops can be used in walls or floors to prevent fire and smoke frompassing through the gaps or openings required for cables, pipes, ducts,or other conduits. Firestops are also used to fill joint gaps that occurbetween walls, between a ceiling and the top of a wall (“head-of-wall”joints), and between a floor and vertical wall (“perimeter” joints).

[0003] So-called “head-of-wall” joints pose a number of challenges forthe firestopping industry. Walls are increasingly being made of gypsumwallboard affixed to a framework of metal studs capped by a horizontallyextending track. Ceilings are increasingly being made by pouringconcrete onto fluted steel. Although the distance between thehorizontally extending track at the top of the wall is often fixed inrelationship to the ceiling, the gypsum wallboards are subject toexpansion and contraction due to motion of other building components,ground settling, or other causes.

[0004] For such head-of-wall joints, it is known to use mineral woolbatt as a thermal resistant firestop material due to its ability toprovide for cyclic movements in the wallboard material. The mineral woolis cut into separate sheets that are appropriately sized depending onthe specific geometry of the fluted steel ceiling. The sheets need to bestacked and compressed (e.g., a minimum 50%) when packed into the jointgap. In some situations, a fireproofing material is spray-applied intothe spaces of the fluted ceiling to supplement the mineral wool in thejoint. In either case, the mineral wool approach requires labor andtime.

[0005] After packing of the mineral wool batt into place above the wall,the construction worker must then spray an elastomeric coating, using aminimum one-eighth inch thickness, against the exposed side surfaces ofthe compressed mineral wool layers. The coating must overlap a minimumof one half inch onto the ceiling and wall surfaces. Thus, the use ofmineral wool batt and elastomeric spray coating provides for the abilityof the resultant firestop to accommodate some cyclic movement(compression and extension) in various components such as the gypsumwallboards on either side of the head-of-wall joint.

[0006] So-called “perimeter barrier” systems also typically employmineral wool and elastomeric coating as firestopping material in thejoint gaps between floors and the surface of a wall, which could be aninterior partition or an external wall. In this case, the mineral woolbatt must be packed tightly in the gap, to improve its fire resistance,and so that upon expansion of the gap due to shrinkage of the floor ormovement of the wall, the mineral wool does not fall out of the gap andinto the floor level below. An elastomeric spray coating is then appliedonto the top face of the packed mineral wool batt, but in most cases thebottom of the mineral wool batt is not coated. This is often due to thefact that the wool batt must be accessed from below, requiring thatladders and spray equipment be moved downstairs and set up.

[0007] One objective of the present invention is to provide a moreconvenient and cost-effective method for installing a thermal barrier inintricately shaped openings and joint gaps such as are found in“head-of-wall” joints, “perimeter” joints, and other variously sizedand/or intricately shaped gaps or openings such as penetrations throughwalls. For example, openings having plastic pipes or plastic-coatedwires often require an intumescent firestopping material for sealing thespace left by the plastic material after it has melted in the fire.Sometimes an intumescent caulk material is inserted into suchpenetration openings. In the case of larger diameter pipes, a metalcollar is used to retain the caulk in place. In other cases, wrapped orbagged mineral wool with an intumscent material is inserted into thehole. In any case, installation of such firestopping is time-consumingand expensive.

[0008] Another objective of the invention is to provide novel thermalbarriers that may be used conveniently and safely in hard-to-reachbuilding or ship vessel joint gaps or holes. For example, the locationof a head-of-wall joint next to an elevator shaft or crawl space wouldrender difficult the installation of mineral wool/coating systems,because the task of coating both sides would be complicated by the lackof convenient access.

[0009] A still further objective of the invention is to enhance safetyof installation. An applicator must climb up and down ladders on afrequent basis when working on head-of-wall joint assemblies. In thefirst instance, there is the fitting and hand-packing of mineral woolmaterial into the joint gap. In the second instance, there is thecoating of elastomeric material to create a continuous surface betweenthe ceiling, firestop, and wall. In both cases, the ladder may requirefrequent repositioning, and this is especially the case where joint gapsextend lengthy distances of ten to twenty feet or more. Frequentclimbing up and down ladders would also be required in “perimeterbarrier” systems if it were desired to apply an elastomeric coating ontothe bottom face of a mineral wool firestop that has been packed betweena floor and a wall, because the installer would need to go to the floorbelow the firestop to coat the bottom face of the mineral wool material.

[0010] In view of the prior art disadvantages, novel thermal barriersand methods are believed to be needed.

SUMMARY OF THE INVENTION

[0011] In surmounting the disadvantages of the prior art, the presentinvention provides a method and system for installing a thermal barrierin openings and gaps in or between building structures such as walls,ceilings, and floors. In so doing, the present invention providesincreased convenience, effectiveness, and safety in comparison to theprior art mineral wool/coating methods. The thermal barriers of thepresent invention have the ability to conform intimately with openingsand gap spaces of various sizes and shapes. The thermal barriers alsohave the ability to permit movement of the various building structuresaround the openings or gaps. In particular, protection on both sides of“head-of-wall” joint assemblies (arising between a wall and ceiling) aswell as upper and downward faces of “perimeter barrier” assemblies(arising between a floor and wall) may be conveniently accomplished bythe thermal barriers and methods of the present invention.

[0012] An exemplary method of the present invention comprises providinga first structure (e.g., building or ship structure such as a floor,wall, or ceiling) having an opening (such as a hole for passage oraccess to cables, wires, pipes, ducts, electrical panels, etc., orproviding first and second structures which define therebetween a gap(such as the joint gap between a wall and a ceiling or floor);introducing into the opening or gap at least one (empty) thermal barriermolding bag that is operative to receive and substantially to contain aflowable firestop material, one that is preferably operative to hardenwithin the bag; and introducing into the thermal barrier molding bag aflowable firestop material to expand the bag within the hold or jointgap, thereby molding a thermal barrier within the hole or joint gap.

[0013] Exemplary thermal barrier molding bags of the invention arepreferably made of thermoplastic film material (although other suitablematerials are hereinafter described) and preferably have at least two ormore openings, preferably of the type that can be opened and closed morethan once, that permit introduction into the bag of a flowable firestopmaterial, e.g., such as hydratable cementitious slurry, an intumescentmaterial, a superabsorbent polymer; polyurethane (foam); hydrated silicagel; inorganic dessicants (e.g., molecular sieves such as zeolites;silica gel; calcium oxide; calcium sulfate; calcium chloride; bariumoxide; phosphorous pentoxide); fibers; mineral wool; fiber glass; ormixture thereof. The molding bag material should be sufficiently sizedand shaped, and flexible enough to permit expansion of the molding bag,upon introduction of the flowable firestop material, and to permitmolding of a thermal barrier within at least a portion of the opening orjoint gap. Preferably, the bags are flexible enough to permit them to betransported in a compact rolled form (when empty) and unrolled intoplace in the opening or gap space (wherein they are expanded and filledwith the flowable firestop material).

[0014] Firestop barriers made in accordance with the above-describedin-situ methods of the present invention provide excellent fireresistance and sealing ability as well as smoke and acoustic barrierproperties. They are also sufficiently strong to resist dislodgementfrom the gap or opening due to pressure (e.g., force from a water hose)and are highly amenable to visual inspection.

[0015] Further features and advantages of the invention are described indetail hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The following detailed description of exemplary embodiments maybe more readily appreciated in conjunction with appended drawings,wherein:

[0017]FIG. 1 is a perspective diagram of a so-called “head-of-wall”joint assembly (PRIOR ART);

[0018]FIG. 2 is a diagram of “head-of-wall” joint assembly along view indirection of arrow “A” shown in FIG. 1;

[0019]FIGS. 3 and 4 are diagrams of exemplary thermal barriers of thepresent invention;

[0020]FIG. 5 is a diagram of exemplary components of an exemplarythermal barrier molding bag having pleats;

[0021]FIG. 6 is a diagram of another exemplary thermal barrier moldingbag having exemplary inlets for introducing a flowable firestopmaterial;

[0022]FIG. 7 is a partial diagram of an exemplary inlet for introducingflowable firestop material into a molding bag;

[0023]FIG. 8 is a partial diagram of an exemplary tube or sleeve inletfor allowing flowable firestop material to be introduced into moldingbags;

[0024]FIG. 9 is a perspective diagram of an exemplary thermal barrierinstalled in a “head-of-wall” joint assembly;

[0025]FIG. 10 is a diagram of another exemplary thermal barrier of thepresent invention installed in a joint gap between wall and floor; and

[0026]FIG. 11 is another exemplary thermal barrier of the presentinvention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0027] The present invention employs one or more thermal barrier moldingbags that may be conveniently placed in openings in structure, such as awall, ceiling, or floor, or conveniently placed in gaps such as aredefined in the joints between walls, ceilings, and/or floors. Themolding bags are placed empty in the hole or gap, and a flowablefirestop material is introduced into the molding bag, thereby expandingthe bag to fill the space within the hole or gap, and the flowablefirestop material is then allowed to harden within the hold or gap toprovide a strong thermal barrier.

[0028] As shown in FIG. 1, a “head-of-wall” joint gap appears betweenthe top of a vertical wall and ceiling (PRIOR ART). In this case, thewall is made by attaching a horizontal metal track 12 or runner to afluted metal ceiling 10 which runs in a perpendicular manner to the wall(12). The ceiling 10 has fluted portions 10B which are somewhat lowerthan the top ceiling portion 10A, and thus a joint cavity 16 is definedbetween the top ceiling portion 10B and the top of the wall, which inthis case is the horizontal track 12. Metal studs 14 are attached to thehorizontal track 12 and connected to the floor below. As shown in FIG.2, gypsum wallboards 18 are affixed on either side of the studs 14 tocomplete the wall assembly (PRIOR ART), and gaps 20 are typically leftbetween the tops of the wallboard 18 and horizontal track 12 to permitmovement of the wallboards 18.

[0029] As shown in FIG. 3, an exemplary thermal barrier 1 of theinvention is made by inserting an empty thermal barrier molding bag 30between the horizontal track 12 and bottom surface 10B of the flutedmetal ceiling 10, before the track 12 is attached to or otherwise fixedinto place against the ceiling surface 10B. A flowable firestop material32 is then introduced into the molding bag 30 to fill the joint space16. Preferably, the thermal barrier molding bag 30 has portion 33thereof extending below the tops of the gypsum wallboards 18 on eitherside of the wall (12/14/18) to protect the exposed gap 20 next to thehorizontal track 12, so that heat and smoke do not penetrate through thewall at the top portion which is not covered by the gypsum wallboard 18.

[0030] Preferably, a spacer material (e.g., resiliently compressiblestrip of foam (STYROFOAM type), foamed rubber, expanded polystyrene,mineral wool, air balloon, etc.) is inserted at the corner gaps 20, toleave a space for cyclic movement of the wallboards 19 when the flowablefirestop material 32 is hardened.

[0031] As shown in FIG. 4, another exemplary thermal barrier 1 of theinvention can be made when the fluted metal ceiling 10 is oriented inthe same direction as the metal stud wall 14. In this case, a barriermolding bag 30 is positioned between the horizontal track 12 and ceilingsurface 10B, with longitudinal edges of the bag (33) extending outwardson either side of the joint between the wall and ceiling, before thehorizontal track 12 is attached to (or otherwise disposed against) theceiling surface 10B. While no joint cavity therefore appears on top ofthe wall in this case (because the spaces defined between ceilingsurfaces 10A and 10B appear on either side of the wall), the corner gaps20 which are customarily left at the top of the gypsum wall board 18nevertheless render the horizontal extending track 12 unprotectedagainst fire. Therefore, a flowable firestop material 32 is introducedinto the molding bag 30, such that a thermal firestop barrier is moldedalong the joint over the corner gaps 20 at the top of the gypsum boards18. Again, it is preferable that a spacer material (foam or mineral woolstrip) be inserted into the gap spaces 20 to permit movement of theboards 18.

[0032] Thus, an exemplary method of the invention comprises inserting athermal barrier molding bag 30 in the joint between two structures, suchas a wall and ceiling, and introducing a flowable firestop material intothe bag 30 so as to expand the bag 30 from an empty shape to a shapeconforming to the space between or around the two structures, andallowing the firestop material to harden inside the bag 30, whereby athermal barrier 1 is molded.

[0033] The thermal barriers of the invention are contemplated primarilyfor use in joint assemblies (e.g., floor-to-floor joint systems,wall-to-wall joint systems, floor-to-wall joint systems, andhead-of-wall joint systems) as well as in “penetration” holes (e.g.,passageways in which pipes, wires, cables, ducts, electrical panels,meters, and other conduits or devices, are situated).

[0034] As shown in FIGS. 3 and 4, the positioned molding bag 30 isfilled with a flowable firestop material 32 that is operative to hardenwithin the bag 30, such as a hydratable cementitious slurry. The moldingbag 30 or bags should allow the introduced flowable firestop material 32to fill the hole or gap space completely, thereby providing an effectivebarrier against passage by heat and smoke. Although FIGS. 3 and 4 depictan application for sealing a joint defined between and/or along twostructures, it will be understood that the exemplary method and bagdevice can be used for filing or otherwise protecting variously sizedand shaped holes in one structure or the joint gaps between two or morestructures. Two or more bags 30 can be used in concert in large holes orjoint gaps, such as by overlapping ends of bags, stacking the bags, orabutting two or more bags in an end-to-end configuration.

[0035] Exemplary molding bags 30 of the invention may be fabricated asone piece “tubes” or sleeves that may be sealed or otherwise closed atthe ends to form a container. More preferably, the bags 30 are made byheat sealing, sewing, adhering, or welding two or more sheets or filmstogether. The films or sheets may be made of different materials. Forexample, plastic sheets having different moduli of elasticity (Young's)can be used. For example, a highly elastic polymer film can be used forthe purpose of allowing the bag to expand into the space of a hole orcavity.

[0036] As shown in FIG. 5, another exemplary thermal barrier molding bag30 of the invention can be made using two separate sheets or films 30Aand 30B. The exemplary sheet or film component designated as 30A, whichin this case is designed to facilitate expansion of the molding bag 30into the joint cavities (designated at 16 in FIGS. 1-3), comprises oneor more pleats 34 made by folding the material. The folded top sheet orfilm 30A is then seamed (such as by welding or sewing) to the bottomsheet or film 30B to obtain the molding bag 30. Preferably, the top film30A has one or more air evacuation holes 36 to permit air to evacuatethe bag 30 when flowable firestop material is introduced. An exemplarycloseable inlet 38 is illustrated in the top portion of FIG. 5, which isdesigned to permit the flowable firestop material to be introduced intothe bag when it is positioned in the hole or joint.

[0037] The bottom sheet or film 30B, as shown in FIG. 5, can thereforebe made of material having a higher modulus of elasticity in comparisonwith the top sheet or film 30A. One reason for using a stronger or morerigid material for the bottom film 30B is that doing so may be moresuitable for the purposes of attaching one or more closeable inlets 38.Another reason is that the bottom face 30B may be sufficiently rigid toretain a fold or arch around the corner gaps 20 shown in FIGS. 2-4. Infurther exemplary embodiments, a flashing material, such as a rigidplastic or metal sheet can be adhered to the bottom face 30B when thebag 30 is installed on top of the wall, with corners bent to coincidewith the corner gaps 20, thereby to resist the weight of the bag 30 andfirestop material 32.

[0038] As shown in FIG. 6, another exemplary thermal barrier molding bag30 of the invention has at least two inlets 38 for introducing flowablefirestop material into the bag 30 while the bag is situated in a hole orjoint. Preferably, the inlets 38 are disposed along both longitudinaledges of the bag 30 (on either top or bottom sheets or films), so thatwhen the bag is installed on top of a wall in a “head-of-wall” jointassembly, an installer can introduce a flowable firestop material intothe bag from either side of the wall.

[0039] Exemplary flowable firestop materials 32 contemplated for use inthe present invention are preferably of the type which are operative tocure or harden inside the bag 30. The term “flowable” as used hereinmeans and includes both dry and liquid materials, and preferably refersto materials that can be pumped under positive pressure through a hose.For example, dry flowable firestop materials can include fibers, such asmineral wool fibers, expanded vermiculite, expanded perlite, shreddedexpanded polystyrene, clay granules or prills, and the like, optionallywith a binder material, such as a latex, a cement and/or gypsum slurry.Exemplary liquid flowable firestop materials can include hydratablecementitious materials, as further explained below, as well as syntheticpolymers (e.g., polyurethane, polyvinyl chloride, polyvinylidenechloride) preferably containing inorganic fillers to reduce flammability(e.g., sand, clay).

[0040] The term “hydratable cementitious” material as used herein refersto material that comprises at least one cementitious binder that beginsto harden when mixed with water. Such a binder may be Portland cement,masonry cement, or mortar cement, gypsum, stucco, Plaster of Paris,aluminous cement, pozzolanic cement, magnesium oxychloride, magnesiumoxysulfate, calcium silicate-hemihydrate, as well as materials such aslimestone, hydrated lime, fly ash, blast furnace slag, and silica fume.The hydratable cementitious materials may in addition optionally includefine aggregates (e.g., sand), coarse aggregates (e.g., crushed stone,gravel, carbon flakes), or other fillers. Further exemplary cementitiousmaterials may optionally contain, in addition to the cementitiousbinder, an intumescent material as will be further describedhereinafter.

[0041] Preferred cementitious materials include pumpable cement and/orgypsum slurries of the kind now employed in the spray-appliedfireproofing industry. Portland cement slurries, optionally havinggypsum, are especially preferred. Other suitable fireproofingcompositions are disclosed in U.S. Pat. No. 4,699,822 of Shu; U.S. Pat.No. 4,751,024 of Shu; U.S. Pat. No. 4,904,503 of Conroy, Hilton,Korenberg; U.S. Pat. No. 4,934,596 of Driscoll, Hilton; U.S. Pat. No.5,352,490 of Hilton, Korenberg; U.S. Pat. Nos. 5,340,612 and 5,401,538of Perito; U.S. Pat. No. 5,556,576 of Berneburg, Freitas, Pisaturo; andU.S. Pat. No. 6,162,288 of Kindt, Hilton, Perito. Such cementitiousslurries are pumpable, because they are typically used in conventionalspray applications, and would permit the thermal barrier molding bags 30to be filled rapidly. While such formulations may involve the use offibers, aggregates, and fillers, these would be rendered optional in thepresent invention because the molding bag 30 would serve primarily asthe means for maintaining the integrity and shape of the cementitiousslurry until it hardens.

[0042] Exemplary hydratable cementitious materials used as flowablefirestop materials 32 in the present invention may further include oneor more admixtures or additives, such as set accelerators, setretarders, water reducers (including superplasticizers and fluidityenhancing agents), rheology modifiers, air entraining agents, pigmentsor colorants, porous aggregates (e.g., shredded expanded polystyrene,expanded vermiculite, perlite, etc.), fibers, rheopectic agents (e.g.,granular attapulgite, sepiolite, or mixtures thereof), surfactants, andother admixtures as conventionally known in the art.

[0043] Exemplary flowable firestop materials 32 may also compriseintumescent compositions which are known in the fireproofing art. Uponexposure to fire, heat, or flames, such intumescent compositions, astheir name implies, expand considerably in terms of thickness to producean insulative layer of char and char foam.

[0044] Numerous patents and publications have disclosed intumescentcompositions containing one or more polymeric materials in combinationwith phosphate-containing materials and carbonific or carbon-yieldingmaterials, and such compositions, as known in the art, are believed tobe suitable for use as flowable firestop materials 30 of the presentinvention. See e.g., U.S. Pat. No. 3,513,114 of Hahn et al.; U.S. Pat.No. 5,487,946 of McGinniss et al.; U.S. Pat. No. 5,591,791 of Deogon;U.S. Pat. No. 5,723,515 of Gottfried; World Patent No. WO 94/17142(PCT/US94/00643) of Buckingham; and World Patent No. WO 98/04639(PCT/US96/12568) of Janci, all of which are incorporated fully herein byreference. In U.S. Pat. No. 3,513,114 assigned to Monsanto, Hahn et al.disclosed intumescent compositions comprising an aqueous dispersion of apolyvinyl acetate-containing emulsion, a solvent plasticizer, andcarbonific ammonium polyphosphates. In U.S. Pat. No. 5,723,515 ofGottfried, it was taught to incorporate an elasticity agent such asvermiculite, perlite, elastomerics, and acrylics, to increase resistanceof the intumescent coating to cracking and shrinking and to improve easeof spraying.

[0045] Another intumescent composition, which the inventors believe issuitable for use as a flowable firestop material 32 in the presentinvention, is disclosed in World Patent Application of Lawrence L. Kuoet al., PCT/US00/18887, which disclosed a composition comprising acomponent package for providing a char and char foam; a polymeric binderin emulsion form operative to form a film when the composition wasallowed to dry; and a crack control agent having a total of 3 to 6carbons and a boiling point in the range of 75-175° C., the crackcontrol agent being represented by the structural formulaR²—O—CH₂—C(R¹)H—O—R³ wherein R¹=—H or —CH₃; and R² and R³ independentlycomprise —H, —R⁴, or —COCH₃, wherein R⁴ comprises a C₁-C₃ alkyl group. Apreferred crack control agent of Kuo et al. comprises alkoxy glycolether, alkoxy glycol acetate, alkoxy glycol ether acetate, or mixturesthereof. An exemplary surfactant package comprises a nonionic alkylarylpolyether alcohol having general formula R-Ø-(OCH₂CH₂)_(x)OH, wherein Ris a C₄-C₈ alkyl group (most preferably, a branched octyl group), Ørepresents a phenylene group, and “x” represents an integer, preferablyin the range of 15-100. Preferred surfactant packages may furthercomprise a dispersant, such as a polyacrylic acid or its salt (e.g.,sodium polyacrylate) or derivatives.

[0046] Other exemplary intumescent materials include graphite flakesimpregnated with sulfuric or nitric acids. Inorganic material flakescapable of exfoliation when heated include vermiculite and perlite.

[0047] Intumscent materials can be used in combination with otherflowable firestop materials 32 in the invention such as Portland cementand/or gypsum containing slurries. For example, in U.S. Pat. No.5,395,571 of Symons, there was disclosed a combination involving gypsumand thermoset resin. Thus, a composition can be made by combining (a) aninorganic base material selected from the group consisting of a calciumsulfate hemi-hydrate, magnesium oxychloride, magnesium oxysulphate and ahydraulic cement; (b) a thermosetting resin which is miscible, solubleor dispersible in water; (c) a suitable amount of a catalyst for thethermosetting resin; (d) water in an amount sufficient to rehydrate theinorganic base material with the water present in the other components;(e) optionally a plasticizer such as a melamine formaldehyde condensate;(f) optionally polyvinyl alcohol; (g) optionally a retarder forretarding the setting time of the inorganic base material; (h)optionally a fibrous reinforcing material; and (i) a foam or a foamingagent. Thus, exemplary flowable firestop materials of the invention maycomprise a hydraulic cementitious slurry containing a portion (e.g.,1-90%) by weight of a polymer, resin, and/or intumescent material, asgenerally known in the art.

[0048] Exemplary flowable fireproofing materials 32 used in theinvention, such as hydratable cementitious slurries, should preferablycontain biocidal agents to combat growth of mold, fungi, and bacteria.These may be supplied in dry powder or liquid form. Materials whichremain wet for long periods of time may be susceptible to mold growth,and thus mold inhibitors should preferably be incorporated into theflowable fireproofing material especially if it is an aqueous mediumsuch as a cementitious slurry. Effective mold inhibition additivesinclude zinc dimethyldithiocarbamate; 1,3 benzenedicarbonitrile;2,3,5,6-tetrachlorothiabendazole; 5-chloro-2-methyl4-isothiazolin-3-oneand 2-methyl-4-isothiazolin-3-one;2,3,5,6-1,3-di(hydroxymethyl)-5,5-dimethylhydantion, ordiiodomethyl-p-tolyl sulfone. More general biocides, such as sodiumhypochlorite or sodium ortho-phenylphenate tetrahydrate, inhibitbacteria as well as molds. For some applications, it is important to usea biocide with minimal toxicity to humans.

[0049] Further exemplary flowable firestop materials 32 may comprisesuperabsorbent polymers, either alone or in combination with, forexample, a hydratable cementitious slurry. A superabsorbent polymer isgenerally a cross-linked, hydrophilic polymer that is operative to bindwater and hence to provide a degree of fire or thermal barrierprotection. Examples of superabsorbent materials include hydrolyzedmaleic anhydride polymers and copolymers including copolymers with vinylethers, styrenes, ethylene, and other olefins, polyvinylpyrrolidone,sulfonated polystyrene, polysulfethyl acrylate,poly(2-hydroxyethylacrylate), polyacrylamide, poly(acrylic acid) andalkali metal salts thereof, poly(acrylic acid alkali metal salt), starchmodified polyacrylic acid and alkali metal salts thereof, poly(starchmodified acrylic acid alkali metal salt), hydrolyzed polyacrylonitrileand alkali metal salts thereof, poly(hydrolyzed polyacrylonitrile alkalimetal salt), poly(vinyl alcohol acrylic acid alkali metal salt), saltsthereof and mixtures thereof. Other options for superabsorbent materialinclude poly(acrylic acid alkali metal salt) such as poly(sodiumacrylate), polyhydroxyalkyl acrylates and methacrylates, polyvinyllactams, polyvinyl alcohols, polyoxyalkylenes, natural or syntheticallymodified polysaccharides, proteins, alginates, xanthum gums, guar gums,and cellulosics. Other examples include monovalent and polyvalentinorganic and organic salts of the foregoing polymers comprising acidicor basic functional groups. Alkali metal salts are preferred for acidfunctional polymers.

[0050] Exemplary molding bags 30 of the invention, as previouslymentioned, should be sufficiently flexible to provide for convenience inpositioning the bag, when empty, into opening or gaps of various sizesand shapes, and to provide for expandability in size, upon introductionof the hydratable cementitious material, whereby the molding bagconforms to at least a portion, or the entirety, of the joint gap oropening. Preferably, the bag may be shipped in roll form such that itcan be unrolled into place conveniently during installation.

[0051] If the molding bag 30 is made of an air-impermeable material suchas plastic film, paper, waxed paper, or impregnated woven or nonwovenmaterial (e.g., impregnated spunbonded nonwoven polyolefin such asTYVEK® envelope material) the bag should preferably have one or more airevacuation holes 36 to permit air to escape when the bag 30 is filledwith a flowable firestop material 32. The holes should be small enough,however, so that leakage of flowable firestop material 32 is minimal.The holes should be preferably located on an uppermost face (on 30B asshown in FIG. 5 for example) because air will be pushed upwards withinthe molding bag 30 by the pressure of incoming flowable firestopmaterial 32. While it may be possible to roll the molding bag 30 tightlyenough initially to expel the air, the simple act of unrolling the bagis likely to introduce air, thus making it advisable to provide airevacuation holes in the bag.

[0052] Exemplary thermal barrier molding bags 30 may comprise a widerange of materials, such as paper, waxed paper, coated paper, cotton,jute, mylar, plastic film, felt, woven fabric, nonwoven fabric (e.g.,impregnated spunbonded polyolefin similar to material used in somemailing envelopes), or a combination thereof. Plastic film materials,and in particular thermoplastics such as polyethylene, polypropylene,polyvinyl chloride, or mixtures thereof, are relatively inexpensive andwould be convenient to use for the applications contemplated by theinventors. Preferably, the plastic film material is completely orpartially transparent, to permit installers and inspectors to ascertainvisually whether the molding bag has been filled adequately with theflowable firestop material 32.

[0053] Other examplary thermal barrier molding bags 30, which aregenerally elongate in shape for insertion into extended joint gaps,preferably have markings or other indicia to serve as indicators forhelping the installer to align placement of the bag within the joint(e.g., the horizontal track 12 on the top of wall). For example, moldingbags 30 can have one or more lines extending longitudinally along thebag to serve as guidelines for positioning the bag correctly on top of awall. Other exemplary bags 30 may have parallel seams or folds or ridgesin the bag that correspond with the edges of the top of the wall (whichis usually about two to six inches in thickness if made of gypsum boardon metal studs, or about eight inches in thickness if made of mortarblocks).

[0054] In further exemplary embodiments, a molding bag 30 can beattached, using adhesive or fasteners, to the horizontal track 12 as aone-piece assembly.

[0055] Exemplary thermal barrier molding bags 30 may have wall (face)thicknesses ranging from 0.1 mils to 60 mils or greater depending uponthe strength of the film or sheet material employed or the number offilms or sheets employed. The molding bags may comprise an elongatedtube shape that is sealed closed at opposing ends by adhesive, heatsealing, stitching, clamping, tying (using string or wire), or othermeans known. The bags may be made by folding over a sheet or film andsealing along peripheral edges to obtain a bag enclosure; or the bag canbe obtained by sealing together two separate sheets or films to form thebag. Exemplary molding bags 20 of the invention may therefore have a“pillow shape” suitable for filling extended longitudinally withinextended joint gaps, such as the “head-of-wall” joint assemblies and“perimeter barrier” assemblies discussed above. Molding bags of theinvention may be made from one layer or two or more layers.

[0056] Exemplary molding bags 30 may comprise plastic films reinforcedwith scrim or mesh, similar to bags which are used for containing meatbones. Such bags are well-known in the food packaging industry and arebelieved to provide increased strength suitable for present purposes.For example, a polypropylene bag can be reinforced with a fiberglassmesh, which decreases the stretchability of the bag.

[0057] As shown in FIG. 7, an exemplary inlet 38 employs a flap 40member that is resiliently biased into a closed position against theopening 39 in the bag material. The flap 40 may comprise an elastomer orthermoplastic material, which is partially attached to the inner surfaceof the bag 30 such as by gluing, hot melt adhesive, sewing, ormelt-sealing. The size and shape of the inlet 38 is preferably chosen tocorrespond with a hose, pipe, or nozzle (not shown) used for conveying aflowable firestop material 32 (e.g., liquid hydratable cementitiousslurry) into the bag 30 (shown by the direction of the arrow “B”). Inthis particular exemplary inlet flap design 28, the pressure of theflowable firestop material 32 in the bag 30 could be used for biasingthe flap 40 into a sealing position (shown by the direction of arrow“C”) against the inner wall of the molding bag 30. Installers would beable to introduce further flowable firestop material 32 into the bagthrough the inlet opening 38, and thus the valve 38/40 is preferablycloseable, and at least one inlet 38 would be positioned along bothlongitudinal edges of the molding bag 30, so that when the bag 30 ispositioned in correct alignment on top of a vertical wall with bothlongitudinal edges hanging down on either side of the wall, the inletopenings 38 are conveniently accessible to workers from either side ofthe wall. In still further exemplary embodiments, the inlet valves 38can be located towards the center along one or both longitudinallyextending edges of the molding bag 30 to minimize the travel distance offlowable firestop material 32 to be introduced into the bag and toincrease the likelihood of filling the molding space within the bag asmuch as possible without leaving air spaces in the hole or joint inwhich the bag is positioned.

[0058] In another exemplary inlet, a screw cap assembly may be employedin a manner similar to the plastic caps on gable-topped orange juice andmilk cartons (e.g., waxed cardboard type). It is also possible to employscrew cap assemblies having a directional valve (e.g., rubber flap asshown in FIG. 7). Still further exemplary valves may include ball valveswherein a ball is rotated between a closed position and open positionwhereby inlet and outlet are connected by a channel running through theball. Other exemplary valves may include a globe style valve, in which aseal moves to press against a “volcano” style orifice. Further exemplaryvalves may include check valves, wherein a flap or other occlusionmember seated on a base over the inlet orifice may be moved to an openvalve position when the flowable firestop material 30 is introduced intothe molding bag, and is then moved into a closed valve position by abiasing means, such as a spring, hinge, or connecting member whichconnects the flap or occlusion member to the base.

[0059] As shown in FIG. 8, exemplary inlet valves may be incorporated aspart of the seamed edges 31 of bags 30 (i.e., the seam 31 otherwisejoins faces 30A and 30B) in the form of tubes or sleeves 42 which areoperative to convey flowable firestop material 30 into the bag 30, inthe direction designated by the arrow “D”, and also operative to becomesealed in a closed position by the pressure of the flowable firestopmaterial 30 within the bag as shown by the arrows designated “E.” Thetube or sleeve 42 may be connected into the bag 30 at the seam using anadhesive, melt-sealing, or other means known; and may extend for anydesirable length outside and beyond the molding bag 30. Using long tubes42 may provide convenience in high head-of-wall joint assemblies locatedseven feet or more above floor level, because it would be possible, suchas by using extended tubes or sleeves 42 which dangle from bagspositioned on the top of the wall, to introduce flowable firestopmaterial 32 into the molding bags without having to ascend a ladder.After filling, the tube or sleeve 42 can be tied or pinched off,reopened, and re-closed using string, rubber band, clip, or otherconvenient means, below the top of the wall.

[0060] As shown in FIG. 9, an exemplary thermal barrier 1 of theinvention can be used to fill one or more gaps or cavities in the“head-of-wall” joint defined between a fluted metal ceiling 10 and ametal stud assembly. The molding bag is positioned between thehorizontal track 12 before the track 12 is fastened to the bottomsurfaces 10B of the ceiling 10 (e.g., using screws or other fasteners).The metal studs 14 are then installed between the track 12 and floor(not shown), and one or more gypsum wallboards 18 are attached to one orboth sides of the track/stud assembly (12/14/18). Preferably, a spacerstrip 21 (e.g., mineral wool or foamed polystyrene or other compressiblematerial) is inserted to protect the gap at the top of the wallboards18. A flowable firestop material is then introduced into the bag 30through an inlet 38, preferably located along a longitudinal edge of thebag 30. Preferably, the bag has a series of pleats 34 allowing the bagto expand when filled with the flowable firestop material. The flowablefirestop material, under force of pressure, should travel along thelongitudinal edges of the bag (designated at 33) which overhang oneither side of the wall assembly (12/14/18), and should preferably fillthe joint cavities between the top of the wall (12) and uppermostceiling surface 10A as well as to fill the bag over the corner joints 20above the wallboards 18.

[0061] As shown in FIG. 10, an exemplary thermal barrier molding bag 30and method of the invention may be used to install a thermal barrier ina so-called “perimeter assembly” in the joint between a vertical wall 44and floor 46. In this situation, it is preferable to use a spacer 21which could be a plastic bag filled with air or a wad or stack ofmineral wool, preferably wrapped in a sleeve or envelope, or otherresiliently compressible object. The spacer 21 may be adhered orotherwise fastened to the floor 46 using known means. The molding bag 30may be attached to the wall 44 such as by using nails or screws alongthe top edge or seam 31 of the bag, using a screw, nail, tack, oradhesive (such as used in structural waterproofing), or other knownmeans. Preferably, the molding bag 30 has one or more inlets 38, such asscrew caps, located towards the top of the bag. The inlets 38 may beused also for the purpose of evacuating residual air in the bag duringthe process of filling it with a flowable fireproofing material 32.Preferably, a portion of the bag extends across the gap between floor 46and wall 44 and rests on a portion of the floor 46 without beingattached or fixed to the floor so as not to impede movement of the flooror wall.

[0062] In further exemplary embodiments of the invention, a thermalbarrier molding bag may comprise two or more compartments or,alternatively, comprise two or more bags connected to each other topermit flowable firestop material to be introduced into one bag (orcompartment) to flow into a second bag (or compartment). As shown inFIG. 11, an exemplary thermal barrier bag 1 may be comprised of aplurality of bags or compartments extending longitudinally in theperimeter joint between floor and wall (or turned sideways, this couldbe an illustration of a ceiling and wall). Bag enclosures are connectedto each other by a plurality of connecting holes or conduits asdesignated at 48. For example, plastic tube-like bags could be connectedto each other periodically along their length, such as by the use ofmelt-sealing or grommets, at holes 48 to permit flowable firestopmaterial to flow from one bag enclosure to another. The bag device 20 ispreferably attached to the wall 44 adhesively or by mechanicalfasteners.

[0063] Exemplary thermal barrier molding bags 30 of the invention mayoptionally have a pressure sensitive adhesive layer, grommets, or othermeans for allowing the bag to be adhered or mechanically attached to awall, ceiling, floor, or other building or vessel structure. Forexample, the bottom side 30B of the bag 30 shown in FIG. 5 can besupplied with a two-sided tape, covered by a releasable sheet, to permitthe bag device 30 to be adhered to the horizontal track 12 before it isfastened to or disposed against the ceiling, as illustrated in FIGS. 3and 4.

[0064] In addition to use in “head-of-wall” joints and “perimeterbarrier” joints, the thermal barriers and methods of the invention maybe used with good advantage in protecting “penetration” openings, suchas “annular” spaces in which cables, ducts, pipes, wires, or electricalpanels are situated. An exemplary method of the invention comprisesproviding an opening in a building structure (e.g., wall, floor, orceiling) having a cable, duct, pipe, wire, or electrical panel in saidopening and defining an annular or otherwise partially occluded spacewithin said opening; inserting into said space a thermal barrier moldingbag; and introducing into said molding bag a flowable firestop material,such as described above. Consequently, the bag inflates and forms a sealwithin the opening to provide a barrier to both sides of the wall,ceiling, or floor opening. In cases wherein the conduit or electricalpanel is not physically in contact with the surrounding wall, ceiling,or floor, then the space in the opening surrounding the conduit orelectrical panel is completely annular (i.e., it surrounds the conduit),and this annular space can be filled, for example, by wrapping a moldingbag at least once around the conduit. If the conduit is a plastic pipeor plastic covered wire or cable, it is preferable to use an intumescentmaterial in the molding bag or outside of the bag but surrounding theconduit, such that if the conduit (e.g., plastic pipe, cable jacket)melts during the fire, then the intumscent material can expand under theeffect of heat to fill the space left by the melted plastic.

[0065] When installed in the hole or joint gap of a building structure,the in-situ molded thermal barriers of the invention are tightlyconformed to the shape of the structure or structuressurrounding/defining the hole or joint gap. It is envisioned thatpreferred thermal barriers of the invention, when installed in jointassemblies, are capable of passing fire endurance tests and hose streamtests in accordance with the “UL Standard for Safety for Tests for FireResistance of Building Joint Systems, UL 2079,” Third Edition, DatedJul. 31, 1988, (Underwriters Laboratories, Inc., Northbrook, Ill.),incorporated fully herein by reference. Fire endurance testing pursuantto UL2079 involves exposing a sample portion of a joint assembly in atest furnace. More accurately speaking, the joint assembly is sealedagainst the furnace with an insulating gasket between the joint assemblyand the furnace (UL 2079). The representative joint assembly can be, forexample, a thermal barrier installed in a head-of-wall joint having oneor more gypsum boards on either side of metal studs to simulate a wall(typically 2.5-8 inches or more in total thickness) and fluted metalplate to simulate a ceiling deck (as described above). One side of thethermal barrier in the joint would be exposed to heat of the furnace inaccordance with a standard time-temperature curve (ASTM E119). Thistime-temperature curve has characteristic points, as follows:

[0066] 50-90 degrees F. (10-32 degrees C.) at 0 minutes

[0067] 1000 degrees F. (538 degrees C.) at 5 minutes

[0068] 1300 degrees F. (704 degrees C.) at 10 minutes

[0069] 1550 degrees F. (843 degrees C.) at 30 minutes

[0070] 1700 degrees F. (927 degrees C.) at 1 hour

[0071] 1850 degrees F. (1010 degrees C.) at 2 hours

[0072] One or more thermocouples are installed against the thermalbarrier on its “cool” side (i.e., unexposed side of joint opposite tothat which is exposed to furnace), and the temperature of thethermocouple is monitored. The test is then conducted until failure isobserved. Failure can be detected by holding a cotton waste pad (100 by100 by 19 mm) directly over the observed crack or hole in the jointsystem, approximately 25 mm from the breached surface, for a period of30 seconds. If the cotton ignites (glows or flames) within this period,then integrity failure has been reached. In the alternative, failure issaid to be attained when the temperature of the thermocouple has risenby at least 325 degrees Fahrenheit above the starting temperature.Accordingly, exemplary thermal barriers of the present invention (madein situ, or, in other words, in the joint gap) have the ability toresist failure, for a minimum period of at least 60 minutes, andpreferably for at least 120 minutes, when tested pursuant to theabove-summarized fire endurance test in accordance with UL 2079.

[0073] Other preferred exemplary thermal barriers of the inventionshould have the ability to maintain barrier integrity when subjected tothe hose stream test, which is also described in UL 2079. For example, ahead-of-wall joint system is subjected to the above-described fireendurance test for a period of time not more than sixty (60) minutes,and then within ten (10) minutes thereafter the joint assembly issubjected to a stream of water delivered through a 2.5 inch (64 mm) hoseand discharged through a National Standard playpipe of correspondingsize equipped with a 1⅛ inch (29 mm) discharge tip of thestandard-taper, smooth-bore pattern without a shoulder at the orifice.The water pressure and duration of the application is to be specified inthe table below: TABLE 1 (Pressure and Duration of Hose Stream Test)Hourly Water pressure at Duration of application, seconds fire ratingbase of nozzle, per square foot (s/m²) of time, minutes Psi (kPa)exposed area^(a) 240 · time <480 45 (310) 3.0 (32)  120 · time <240 30(210) 1.5 (16)   90 · time <120 30 (210) 0.90 (9.7)      time <90 30(210) 0.60 (6.5)

[0074] Accordingly, preferred thermal barriers of the invention (made inthe joint gap), subsequent to application of the aforementioned fireendurance test, should be able to pass the hose stream test, inaccordance with UL 2079. In other words, the thermal barriers shoulddemonstrate the ability to resist dislodgement from the joint gap bywater pressure from a hose, for a given period of time, as indicatedabove in the chart with respect to the applicable hourly fire ratingtime. The nozzle orifice is to be 20 feet (6.1 m) from the center of theexposed surface of the joint system if the nozzle is so located that,when directed at the center, its axis is normal to the surface of thejoint system. If the nozzle is unable to be so located, it shall be on aline deviating not more than 30 degrees from the line normal to thecenter of the joint system. When so located its distance from the centerof the joint system is to be less than 20 feet (6.1 m) by an amountequal to 1 foot (305 mm) for each 30 degrees of deviation from thenormal (UL 2079).

[0075] The foregoing discussion and examples are provided forillustrative purposes and not intended to limit the scope of theinvention as claimed.

We claim:
 1. A method for installing a barrier, comprising: providing afirst structure having a hole, or providing a first structure and asecond structure defining therebetween a gap; introducing into said holeor gap at least one thermal barrier molding bag that is operative toreceive and substantially to contain a flowable firestop material; andintroducing, into said at least one thermal barrier molding bag, aflowable firestop material, thereby molding a barrier.
 2. The method ofclaim 1 wherein said first structure is a vertical wall.
 3. The methodof claim 2 wherein said vertical wall comprises gypsum board supportedby framework.
 4. The method of claim 1 wherein said gap resides in thejoint between a wall and a ceiling or floor.
 5. The method of claim 4wherein said gap is between a vertical wall, which comprises gypsumboard supported by framework, and a ceiling which comprises flutedmetal.
 6. The method of claim 4 wherein said gap is between a verticalwall and a floor.
 7. The method of claim 1 wherein said gap is betweentwo walls.
 8. The method of claim 1 wherein said flowable firestopmaterial comprises a hydratable cementitious slurry comprising Portlandcement, gypsum, or mixture thereof.
 9. The method of claim 8 whereinsaid hydratable cementitious slurry comprises Portland cement.
 10. Themethod of claim 8 wherein said hydratable cementitious slurry comprisesat least one admixture selected from set accelerators, set retarders,water reducers, superplasticizers, fluidity enhancing agents, rheologymodifiers, air entraining agents, pigments or colorants, aggregates,fibers, rheopectic agents, surfactants, antibacterial agents, or mixturethereof.
 11. The method of claim 8 wherein said hydratable cementitiousslurry comprises Portland cement, and said slurry further comprises anair entraining agent and a water reducing agent.
 12. The method of claim1 wherein said flowable firestop material comprises an intumescentmaterial.
 13. The method of claim 1 wherein said flowable firestopmaterial comprises a superabsorbent polymer, a desiccant, hydratedsilica gel, or mixture thereof.
 14. The method of claim 1 wherein saidthermal barrier molding bag comprises material selected from the groupconsisting of paper, waxed paper, coated paper, cotton, jute, mylar,plastic film, felt, woven fabric, nonwoven fabric, or a mixture thereof.15. The method of claim 14 wherein said thermal barrier molding bagcomprises plastic film.
 16. The method of claim 15 wherein said thermalbarrier molding bag comprises plastic selected from polyethylene,polypropylene, polyvinyl chloride, or a mixture thereof.
 17. The methodof claim 15 wherein said thermal barrier molding bag comprises asubstantially transparent plastic film.
 18. The method of claim 15wherein said thermal barrier molding bag comprises a first plastic film,a second plastic film, said first and second films being heat-sealedtogether to form said bag.
 19. The method of claim 18 wherein at leastone of said first or second plastic films comprises at least one foldedpleat.
 20. The method of claim 1 wherein said at least one thermalbarrier molding bag comprises a plurality of folded pleats.
 21. Themethod of claim 15 wherein said thermal barrier molding bag has agenerally elongated body having opposed longitudinally extending firstand second edges, said molding bag further having a plurality of holesalong said elongated body to facilitate evacuation of air when aflowable firestop material is introduced into said molding bag.
 22. Themethod of claim 21 wherein said thermal barrier molding bag has at leastone inlet for permitting flowable fireproofing material to be introducedinto said bag.
 23. The method of claim 22 wherein said thermal barriermolding bag has at least one inlet located along said first and secondlongitudinally extending edges, thereby to permit filling on either sideof said thermal barrier molding bag when installed on the top of a wall.24. The method of claim 21 wherein said thermal barrier molding bag hasflap members for allowing flowable firestop material to flow into saidmolding bag, when situated in a head-of-wall joint, such that firestopmaterial can flow into a portion of the molding bag at a level locatedbelow the top of the wall.
 25. The method of claim 1 wherein saidthermal barrier molding bag has at least two compartments connected toeach other to permit flowable fireproofing material introduced into afirst compartment to flow into a second compartment.
 26. The method ofclaim 1 wherein said thermal barrier molding bag is connected to anotherthermal barrier molding bag, whereby flowable firestop materialintroduced into one of said molding bags is able to flow into theconnected molding bag.
 27. The method of claim 1 wherein said thermalbarrier molding bag is inserted into a hole of a structure, saidstructure hole having pipe, duct, cable, wire, or electrical panellocated therein.
 28. The method of claim 1 wherein said flowablefirestop material is allowed to harden.
 29. The method of claim 28wherein said molding bag containing hardened firestop material has afire endurance, when tested in accordance with UL 2079, of at least 60minutes.
 30. The method of claim 29 wherein said molding bag containinghardened firestop material has a fire endurance, when tested inaccordance with UL 2079, of at least 120 minutes.
 31. The method ofclaim 29, wherein said molding bag containing hardened firestop materialis capable of avoiding failure in accordance with the hose stream test(UL 2079), in at least one of the hourly fire rating times indicatedbelow: Hourly Water pressure at Duration of application, seconds firerating base of nozzle, per square foot (s/m²) of time, minutes Psi (kPa)exposed area^(a) 240 · time <480 45 (310) 3.0 (32)  120 · time <240 30(210) 1.5 (16)   90 · time <120 30 (210) 0.90 (9.7)      time <90 30(210) 0.60 (6.5)


28. A firestop made in accordance with the method of claim
 1. 29. Ajoint assembly comprising at least two adjoining structures definingtherebetween a gap, said gap containing a thermal barrier made inaccordance with the method of claim
 1. 30. A firestop molding bag,comprising: a first face, a second face, said first and second facesbeing connected to each other around their peripheral edges therebydefining a bag enclosure for receiving a flowable fireproofing material,a least one of said first and second faces having a plurality of holesoperative to release air pressure when said bag enclosure is filled witha flowable fireproofing material, at least one of said first and secondfaces having pleats to permit three-dimensional expansion of the bag.31. The thermal barrier molding bag of claim 30 wherein at least one ofsaid first and second faces comprises a transparent plastic film, saidbag further having at least one inlet for introducing into said bag aflowable fireproofing material.
 32. The thermal barrier molding bag ofclaim 31 wherein said bag has two opposed ends defining therebetween anelongated body, said elongated body having opposed longitudinallyextending seams, and at least one inlet located along each of saidopposed longitudinally extending seams to permit a flowable fireproofingmaterial to be introduced into said bag.